Substance use treatment; Treatment for co-occurring substance use plus either serious mental health illness in adults/serious emotional disturbance in children; Outpatient; Regular outpatient treatment; Does not use MAT for opioid use disorders; Private for-profit organization; State Substance use treatment agency; State mental health department; State department of health; IHS/Tribal/Urban (ITU) funds; Medicaid; Private health insurance; Cash or self-payment; State-financed health insurance plan other than Medicaid; Sliding fee scale (fee is based on income and other factors); Clients with co-occurring mental and substance use disorders; Clients who have experienced sexual abuse; Clients who have experienced trauma; Comprehensive mental health assessment; Comprehensive substance use assessment; Outreach to persons in the community; Screening for tobacco use; Screening for substance use; Screening for mental disorders; Professional interventionist/educational consultant; Aftercare/continuing care; Discharge Planning; Naloxone and overdose education; Self-help groups; Mentoring/peer support; Treatment for gambling disorder; HIV or AIDS education, counseling, or support; Hepatitis education, counseling, or support; Substance use disorder education; Smoking/vaping/tobacco cessation counseling; Individual counseling; Group counseling; Family counseling; Marital/couples counseling; Smoking permitted in designated area; Children/adolescents; Female; Male; Domestic violence services, including family or partner; Early intervention for HIV; Mental health services; Social skills development